Convertible blower/vac units are in common use by homeowners and professionals for the removal of debris from yards and driveways. A convertible blower/vac is a device which can be used as a blower or which can be converted to operate as a vacuum.
In blower operation, typical blower/vac units provide a sweeping action created by the production of a fast moving stream of air from a rotating impeller within a housing. A removable exhaust or blower tube generally carries the air stream from the housing of the unit so that a nozzle at the outlet of the blower tube can be near the ground while the unit is being held by the operator. The nozzle at the end of the blower tube is generally smaller than the outlet port on the housing of the unit, thus causing a higher velocity air stream at the nozzle and allowing for greater precision and force in blowing debris across a surface.
Conversion from the blower mode to the vacuum typically requires removing the blower tube from the housing outlet and placing a debris catching vacuum bag on the outlet. An air inlet cover is removed from the housing inlet and a vacuum tube is placed over the inlet. In vacuum operation, the hand held device draws air and debris through the vacuum tube. Debris is reduced as it is drawn up through the impeller. The debris is then propelled into the vacuum bag for disposal.
Modern units are typically hand-held and, therefore, are made of lightweight materials and utilize lightweight power sources. The two most common power sources for the units are electric and gasoline motors.
One prior art portable blower/vac is disclosed in U.S. Pat. No. 5,222,275 issued to Baker et al. on Jun. 29, 1993. Baker discloses a convertible electric blower/vac with a removable air inlet cover and means for attaching a blower tube, a vacuum bag, and a vacuum tube to the housing.
U.S. Pat. No. 4,644,606 issued to Luerken et al. on Feb. 24, 1987 discloses a convertible gas engine powered blower/vac with a vacuum tube with a generally circular cross-section. Luerken et al. also discloses a blower tube with a generally circular cross-section. Luerken et al. also discloses an air inlet cover with no means for adjusting the inlet area although the air volume and speed through the blower/vac can be adjusted by varying the throttle setting of the gas engine which drives the impeller.
U.S. Pat. No. 4,694,528 issued to Comer et al. on Sep. 22, 1987 discloses a convertible electric blower/vac with a removable air inlet cover including means for adjusting the air inlet area of the cover. The means for adjusting the inlet area includes a series of axially (in relation to the fan motor shaft) disposed air inlet openings and a concentrically mounted air choke with a series of axially disposed spokes. When the choke is rotated such that the choke spokes cover the air inlet openings, the air inlet area is reduced and the resultant airflow through the blower/vac is reduced. When the choke is rotated such that the choke spokes move away from and expose the air inlet openings, the inlet area is increased and the resultant air flow through the blower/vac is increased. Comer et al. also discloses a blower tube and a vacuum tube of a generally circular cross-section. The vacuum tube is attached over the air inlet of the housing by means of a bayonet-type fitting while the blower tube is attached to the housing outlet by means of a shallow, fine pitch screw thread. The air inlet cover includes a pressure ring for increasing the efficiency of the impeller when the unit is operated in the blower mode. The pressure ring is integral with the member forming the air inlet openings but is a separate component from the air inlet cover proper.
U.S. Pat. No. 4,413,371 issued to Tuggle et al. on Nov. 8, 1983 discloses a power blower with a blower tube that tapers from a generally circular cross-section at its upstream end to a generally rectangular cross-section at its downstream end.
U.S. Pat. No. 4,325,163 issued to Mattson et al. on Apr. 20, 1982 discloses a convertible electric blower/vac with a removable air inlet cover. The air inlet cover does not include any means for adjusting the air inlet area of the cover. Mattson et al. also discloses a blower tube with a generally circular cross-section wherein the blower tube is joined to the housing outlet by means of a friction fit. The vacuum tube is also connected to the housing by means of a friction fit while the vacuum bag is attached the housing outlet by means of a strap which secures the bag inlet around the housing outlet.
U.S. Pat. No. 4,945,604 issued to Miner et al. on Aug. 7, 1990 discloses a portable blower with a blower tube having a circular cross-section at its upstream end and a generally rectangular cross-section at its downstream end. The blower tube is removably connected to the blower by means of a bayonet-type fitting arrangement.
U.S. Pat. No. 2,586,145 issued to Breuer et al. on Feb. 19, 1952 discloses a convertible electric blower/vac with a removable nozzle for use in the blower mode. The nozzle is removably connected to the downstream end of the blower tube by means of sliding engagement collar and pin connector system. A resilient finger cooperates with the sliding engagement collar to retain the removable nozzle on the blower tube. The removable nozzle has generally circular cross-section at its upstream end and a generally rectangular cross-section at its downstream end. The outlet portion of the nozzle is disposed at an angle of approximately 60.degree. from the longitudinal axis of the neck or upstream portion.
U.S. Pat. No. 5,035,588 issued to Sadler et al. on Jul. 30, 1991 discloses a convertible gasoline powered blower/vac with means for resiliently and frictionally engaging a blower tube or a vacuum outlet tube into the housing outlet. The blower tube has a generally circular cross-section at its upstream end and a generally rectangular cross-section at its downstream end.
U.S. Pat. No. 4,553,284 discloses a vacuum cleaner universal nozzle made from a resilient material which is manually deformable such that the inlet opening and configuration can be altered by the operator to suit operating conditions.
U.S. Pat. No. 2,068,496 issued to Linghammar on May 21, 1936 discloses a vacuum tube with a generally cylindrical upstream portion and a funnel shaped downstream portion. The funnel shaped downstream portion is made of a flexible material and can thus be deformed to conform to irregular shape surfaces. Linghammar also discloses a series of longitudinal ribs running along the inner surface of the funnel shaped downstream portion. These ribs prevent the flexible funnel shaped downstream portion from collapsing due to the partial vacuum created by the fan.
Toro parts catalog, form No. #3316-626, 1993 copyright to The Toro Company discloses a convertible electric blower/vacuum with a removable air inlet cover. The air inlet cover includes means for adjusting the air inlet area. The means for adjusting the air inlet area includes a series of axially (in relation to the fan motor shaft) disposed air inlet openings and a concentrically mounted air choke with a series of axially disposed spokes. When the choke is rotated such that the choke spokes cover the air inlet openings, the air inlet area is reduced and the resultant airflow through the blower/vac is reduced. When the choke is rotated such that the choke spokes move away from and expose the air inlet openings, the inlet area is increased and the resultant airflow through the blower/vac is increased. The convertible electric blower/vac also includes a pressure ring that is integral with the member forming the air inlet openings, but the pressure ring is a separate component from the air inlet cover proper.
Paramount operator's manual #534-886570-8, 1993 copyright to Paramount Division of WCI Outdoor Products, Inc. discloses a convertible electric blower/vac with a removable air inlet cover that includes means for adjusting the inlet area through the air inlet cover. The means for adjusting the inlet area includes a series of radially disposed openings on the air inlet cover. A pivoting choke member is fastened to the air inlet cover and includes a series of radially disposed spokes. When the choke is rotated such that the spokes obstruct the radially disposed openings on the cover, airflow through the blower/vac is reduced. When the choke is rotated such that the spokes move away from the cover openings, then airflow through the blower/vac is increased. The Paramount unit does not include axially disposed choke spokes or inlet cover openings, nor does it include a pressure ring.
The Paramount PB-100 power blower manufactured in 1990 and shown in the Paramount parts list #534-500069 dated Dec. 12, 1990, discloses an electric blower including an air inlet cover with an adjustable choke member. The air inlet cover and the choke member each include a series of radially disposed spokes and air inlet openings as well as a series of axially disposed spokes and air inlet openings. The choke member is mounted concentrically on the air inlet cover and can be rotated such that in one position the spokes of the choke member cover the air inlet openings of the air inlet cover. In the other position, the spokes of the choke member are rotated away from the air inlet openings, thus exposing the openings and allowing air to pass through the air inlet cover. The air inlet cover of the Paramount PB-100 does not include a pressure ring for increasing the efficiency of the impeller in the blower mode.
The present system offers an alternate convertible blower/vac. In particular, the present invention includes a convertible electric blower/vac with an improved air inlet cover and adjustable choke member. The present invention also includes an improved system for attaching a blower tube and a vacuum bag assembly to the housing outlet of the blower/vac housing. The present invention also includes an improved vacuum tube for use of the blower/vac in the vacuum mode. The present invention also includes means for reducing unwanted rotational deflection of the blower tube when it is engaged on the housing outlet.